Conditions affecting beliefs about visual perception among children and adults

Children and adults were tested on their beliefs about whether visual processes involved intromissions (visual input) or extramissions (visual output) across a variety of situations. The idea that extramissions are part of the process of vision was first expressed by ancient philosophers, including Plato, Euclid, and Ptolemy and has been shown to be evident in children and in some adults. The present research showed that when questions about vision referred to luminous as opposed to non-luminous objects, under certain conditions there was some increase in intromission beliefs, but almost no corresponding decline in extramission beliefs, and no evidence of transfer of intromission responses to questions referring to nonluminous objects. A separate study showed that college students, but not children, increased their extramission responses to questions providing a positive emotional context. The results are inconsistent with the idea that simple experiences increase or reinforce a coherent theory of vision. The results also have implications for understanding the nature of beliefs about scientific processes and for education.